This section provides background information related to the present disclosure which is not necessarily prior art.
Chucks for holding a drill bit or a screwdriver bit have been known for many years. Chucks often times comprise an inner cylindrical hollow core to which a plurality of jaws are held at an angle. The jaws may move into and out of the hollow core thereby clamping a bit there within. In order to advance or retract the jaws, the jaws have a threaded portion that cooperates with a threaded collet member that is generally held circumferentially around the jaws in a rotatable, but axially immovable manner. Thus, on rotation of the collet member, the threads cooperate to advance or retract the jaws.
Whilst the above mode of advancing or retracting the jaws is generally acceptable, it does suffer from some short-coming. In order for the chuck to accommodate bits of significantly different diameters, the amount by which the collet member must be rotated to advance or retract the jaws can be considerable. In situations where a user must frequently change between larger and smaller diameter bits, the operation of a chuck in the usual manner can be very inconvenient. Moreover, because conventional chucks are hand-tightened, the amount of force that secures a bit within a chuck is dependent upon the strength of the person using the tool.